Mod naming rule and engine UI in engine mods

Mods are renamed by role (shell2d_base, menu_base, ui_base, live2d_base,
editor_tools, cthangover_story, cthangover_murakami, cthangover_party) and
every reference follows. Engine UI prefabs (dialog, answers, message, game
menu, inventory, map, skills) and their panel entries moved out of the story
mod into the subsystem mods; the card_novel and vn_starter_novel collections
are removed.

manifest.json

@@ -8,6 +8,19 @@
   "sources": [
     "src/**/*.cs"
   ],
-  "depends": ["interface>=1"],
-  "ui": []
+  "depends": ["ui_base>=1"],
+  "ui": [
+    {
+      "id": "skills",
+      "kind": "panel",
+      "slot": "ModBeforeUIPanel",
+      "scene_path": "scenes/ui/skills_panel/skills_panel.tscn",
+      "button": {
+        "icon": "skills",
+        "locale": "ui/skills/title",
+        "index": 40
+      },
+      "priority": 10
+    }
+  ]
 }